Spreading Butterflies

Moths and butterflies look better and are
easier to identify if their wings are spread properly.
A spreading board is used to do this. Adjustable
spreading boards for use with different sized
butterflies can be bought from biological supply
houses. The slots in the cover of the styrofoam box
you might have bought for 4-H Entomology Unit I
can also be used for spreading. If you don't have
either of these, you can make a spreading board
according to the instructions given in the Optional Exercises.

Put an insect pin through the center of the
thorax of a freshly killed butterfly. If the insect
has dried, use a relaxing jar to soften it. (See
Optional Exercises for instructions on making
a relaxing jar.) One-fourth inch of the pin
should be exposed above the thorax. Make
sure the insect does not tip from side to side or
from front to back on the pin.

Push the pin straight down in the center of the
slot of your pinning board until the outstretched
wings are just level with the surface of the
pinning board.

Insert an insect pin lightly in each front wing
near the front margin and just behind one of
the heavy wing veins. Move the front wings
forward gently until the hind margins of the
front wings are in a straight line, at right angles
to the body.

With a pin placed behind a heavy vein in the
hind wing, move each hind wing forward until
the gap between the front wing and hind wing
is closed to just a notch, as shown on the right
side of the illustration below.

Cut some narrow strips of paper and lay them
over the wings. Pin them in place as shown.
Remove the other pins that are through the
wings. The pins holding the paper strips in
place should not go through the wings but
should be close to them to keep enough
pressure on the wings to prevent their slipping
out of place. Some entomologists use
transparent paper so they can see if the wings
have slipped out of place while the specimen is
drying. Paper that is too thin will not give
enough pressure on the wings. If the abdomen
tends to sag, it can be propped up with pins
until it dries. You can also use pins to keep the
antennae in place while the specimen dries.
Depending on the moisture in the air, the
specimen should remain on the board from
four to eight days.